1. Technical Field
The present invention relates to a semiconductor memory apparatus, and more particularly, to a circuit for generating a clock of a semiconductor memory apparatus.
2. Related Art
In general, as shown in FIG. 1, a circuit for generating a clock of a semiconductor memory apparatus includes a resistor R1, a capacitor C1, and a Schmitt trigger 1. A resistance of the resistor R1 changes according to temperature. A threshold voltage of a transistor that constitutes the Schmitt trigger 1 changes according to temperature. Therefore, the frequency of a clock clk that is output by the circuit for generating a clock according to the related art changes according to temperature.
The clock clk output by the circuit for generating a clock according to the related art changes in a range of approximately 10 to 15% when temperature changes from 15 degrees below zero to 100 degrees above zero. The semiconductor memory apparatus that is designed according to the clock clk having predetermined frequency performs an erroneous operation when the frequency of the clock clk changes.